Organocatalyzed enantioselective aldol reaction of 1H-pyrrole-2,3-diones

TETRAHEDRON LETTERS

卷:53

Article

Bhanushali, Mayur¹  Zhao, Cong-Gui¹ 

[1] Univ Texas San Antonio, Dept Chem, San Antonio, TX 78249 USA

关键词: Aldol reaction;    1H-Pyrrole-2,3-dione;    3-Hydroxy-1H-pyrrol-2(3H)-one;    Organocatalysis;    Enantioselective;    Proline;    Cinchona alkaloid;   

DOI  :  10.1016/j.tetlet.2011.11.056

来源: Elsevier

【 摘 要 】

The enantioselective cross aldol reaction of 1-benzyl 4,5-dioxo-2-aryl-4,5-dihydro-1H-pyrrole-3-carboxylates and ketones was studied with praline derivatives or cinchona alkaloid-derived primary amines as the catalysts for the first time. trans-4-Benzoyloxy-L-proline (15) was found to be the best catalyst for acyclic ketones. For cyclohexanone, the best results were achieved with 9-deoxy-9-epi-aminoquinine (18) as the catalyst in the presence of racemic 1,1'-binaphthyl-2,2'-diyl hydrogen phosphate (19) as the cocatalyst. Using these protocols, 3-alkyl-3-hydroxy-1H-pyrrol-2(3H)-one derivatives were obtained in excellent yields and good to high ee values (up to 94% ee). (C) 2011 Elsevier Ltd. All rights reserved.

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